Let-off mechanism for looms



Ma.mb 12, 1929,. E. c. BURNHAM 1,704,911

LET-OFF MECHANISM LOOKS Filed'Feb. 18, 1928 S Sheets-Sheet 1 Fig.1.

, lh'venTon- Edward C. Burnhum March 12, 1929. c, BURNHAM 1,704,911 LET OFF MECHANISM FOR LOCMS Filed Feb. 18, 1928 3 Sheets-Sheet 2 Fig. 2.

32 35 35 4O 34 as 47 8 4s InvenTor.

Edward C. Burn h a m ATTys.

'Marc h12,1929. EQBURNH M v 1,104,911

LET-OFF MECHANISM FOR LOOMS Filed Feb. 18, 1928 5 Sheets-Sheet 5 lnvenTor. Edward C. Burnham byw kfwn-GJ Patented Mar. 12, 1929;

UNITED STATES PATENT OFFICE.

EDWARD G. BURNHAM, OF HO YEDALE, MASSACHUSETTS, ASSIGNOR '10 DRAIPEB PORATION, OF HOPEDALE, MASSACHUSETTS, A CORPORATION 01' MAINE.

LET-OFF MECHANISM FOR LOOMS.

Application filed February 1a, 1928. Serial No. 255,377.

This invention relates to improvements in let-off mechanisms for looms and the rincipal object of the invention is to rovlde a let-oif mechanism which will permit the use of warp beams of larger diameter than those ordinarily used, thereby enabling warp beams to be employed which will' carry a greater length of warp. The use; of such larger warp beams is articularly desirable where a coarse warp is eing used.

A further object of the invention is to provide mechanisms for supporting and actuating a large warp beam which can .be

applied to a usual type of loom without,

modification of the general loom structure.

Warp beams are usually provided with attached gears of a standard s1ze or diameter which engage and are driven by a pinion upon a suitable actuating shaft.

A further object of the present invention is to provide mechanism for rotating the usual warp beam actuating shaft in a direction which will permit the interposition of means intermediate of the pinion and gear operable to transmit rotation from the pinion to the gear without changing the gear ratio therebetween, so that the axes of the gear and pinion may be spaced aparta greater distance than the combined length of the radii of said gear and pinion, thus enabling the em loyment of a lar er warp beam upon a usual type of loom. This is accomplis ed in the present mechanism by providing means operable to rotate the warp beam actuating shaft in the same direction as the desired warp delivery direction of the warp beam and mterposing between the pinion and shaft an idle r which will transmit rotation from the p nion to the gear without change in speed ratio therebetween'irrespective of the size of the idle gear employed.

A further object of the invention coning the idle gear so that such di erent idle gears may be emplo ed as may be required in accordance with t e spacing of the. pinion and gear.

A preferred embodiment of the invention is illustrated herein as ap lied to let-off mechanisms of the type disc osed in patents effected actuating shaft. sists in adjustably and detachabl supportacting shaft and the war beam actuating shaft is positively, rotated by a pawl and ratchet mechanism operated from some regularlymoving part of the loom, such as the lay, to advance the warp the required distance at each beat-up. The extent this advancing movement is determinedb the extent to which the actuating pawl is retracted 'rior to each advance 1 and this is y co-operating mechanisms under the conjoint controlof the tension upon the warp and the diameter of the yarn mass. A speed reducing mechanism is employed to transmit rotation from the ratchet to the warp beam actuating shaft and the warp beam actuating shaft is rotated in the con struction disclosed in the patents aforesaid direction of rotation of the warp beam.

The present invention contemplates the provision of mechanism for causing the ratchet to rotate the war beam actuating mechanism in the same direction as the required 'warp delive direction of rotation of the warp beam, t us enabling the inter-. position between the pinion of the warp beam actuating shaft and the warp beam gear of an idle gear,'o r other suitable mechanisms, which will transmit rotation from the warp beam actuating shaft to the war beamwithout modi ing the gear ratio t ierebetween, thus enab g the warp beam shaft to be located at a greater distance from theiactuatin shaft than theQcombined radi fa-the warp earn gear and the pinion fu n the warp beam actuating shaft consequently permitting the employment 0 a large-"beam. Furthermore, such construction enables the emplo ment of anidle earpffiany size so that t e warp beam sha ma "be located at any desired distance from the warp beam By reason of the resent invention standard gears for warp eams may be employed lflp'on much larger warp beams than heretoore.

The speed reducing mechanism employed in the construction disclosed in the patents aforesaid comprises -a non-rotatable gear loosely and eccentrically mounted upon the ratchet aforesaid and an annular internal gear. in meshfth'erewith and fast upon the warp beam actuating shaft. The pawl and ratchet gears rotate t e warp beam actuating' sh" mechanism together with the speed reducifigi in the opposite direction to the desired warp beam dehvery direction of rotation as aforesaid so that the pinion upon the actuating shaft, meshing directly with the warp beam' gear, rotates the warp beam in a proper direction.

The present invention contemplates the employment of a speed reducing unit which will rotate the warp beam actuating shaft in the same direction as the desired direction of rotation'of the warp beam, thereby enabling the interposition of an idle gear between the pinion of the warp beam actuating shaft and the warp beam gear. Means desirably are provided for securing the speed reducing unit upon the warp beam actuating shaft so that it can be readily removed and the usual speed reducing mechanism, disclosed in the patents afores said, applied thereto.

By reason of the present invention therefore, warp beams having gears of usual size, driven directly from the warp beamv actuating shaft, and warp beams of larger size, driven through an intermediate idle gear from the warp beam actuating shaft, may be employed on the same loom by merely changing the speed reducmg mechanism, and where, a larger warp beam is employed providing suitable means, such as brackets, to'support the shaft of the warp beam at a greater distance from the warp beam actuating shaft than the combined iadii of the Warp beam gear and the pinion upon the war beam actuating shaft.

A preferre embodiment'of the invention is illustrated in the accompanying drawings, in which,

Fig. 1 is a side elevation of a portion of the loom embodying the let-off mechanism;

Fig. 2 is a front elevation, partially in vertical section, of the construction shown in Fig. 1;

Fig. 3 is a detail view, partially in section, illustrating the manner in which the internal gear of the speed reducing mechanism is prevented from rotation; and,

Fig. 4 is a detail view showing the connection of the pawl actuating lever to an arm on the rocker shaft of the loom.

The loom illustrated in the accompanying drawings comprises the usual loom sides 1, one of which is shown. provided with extensions 2 having at their upper ends recesses 3 to receive the shaft of a usual warp beam, and a warp beam actuating shaft 4 which is mounted in a bearing 5 in a bracket 6 which is suitably secured to the cross girder 7 of the loom. In the construction shown the bearing 5 extends through the web of the loom side 1. In the resent construction a large warp beam 8 is employed and its shaft 9 is mounted in suitable bearings 10 in brackets 11 which are detachably secured to the loom side by bolts 12. The

bracket desirably is provided with an extension 13 which rests upon the shoulder of the extension 2 which is usually employed to support the warp beam shaft and may be secured thereto by suitable bolts or screws 14.

By reason of this construction brackets of such different lengths may be employed as may be required properly to support warp beams of different sizes. The warp beam 8 is provided with a gear 15 which 1s usually attached to it and which in usual constructions meshes with a pinion 16 fixedly secured upon the warp beam actuating shaft 4. In the present construction, however, the shaft 9 of the warp beam is located at a greater distance from the warp beam actuating shaft 4 than the combined radii of the warp beam gear 15 and the pinion 16, and an idle gear 17, which meshes with the pinion 16 and gear 15, transmits rotation from the pinion 16 to the gear 15, the-gear 15 being driven in the same direction as the required delivery direction of rotation of the warp beam by mechanism which will hereinafter be more'fully described.

An idle gear 17 of any desired size may be employed as it merely transmits rotation from the pinion 16 to the gear 17 without affecting the speed ratio of said pinion and gear. Desirably, therefore, means are provided for adjustably or detachably supporting the idle gear 17. A convenient mecha-- nism .which is illustrated in the drawings comprises a-bracket 18 having a stud shaft 19 extending therefrom upon which the idle gear 17 is rotatably mounted and detachably secured by a cotter pin 20. The-bracket 18 is adjustably connected to a iboss 21 extending upwardly from the bearing 5 of the warp beam actuating shaft 4 by a bolt 22 extending through said bracket into a slot in the bracket 18 which supports the idle pinion. By virtue of this adjustment the stud shaft may be positioned as maybe required for usual different spacings of the warp beam shaft from the actuating shaft without changing the idle gear. This adjustment also provides means wherebyidle gears of different sizes may be employed for unusual spacings of the warp beam gear and the actuating shaft. I

The mechanism for rotating the actuating shaft *1 in the present construction is in many particulars similar in construction to that disclosed in the patents aforesaid, but includes speed reducing mechanism operable to rotate the warp beam actuating shaft in the same direction as the warp delivery rotation of the war beam, which is opposite to the direction of rotation of the shaft disclosed in the'patents aforesaid.

In the construction illustrated the sheet of warps 23 running from the warp beam 8 passes over a pulley or drum 24 the shaft of which is adapted to bemounted in any one of a series of sockets in bearings 27 bolted to the usual brackets which are secured to the loom sides, and thence over the whip roll 26 to t e harnesses of the loom (not shown). The shaft of the whip roll 26 is carried by arms 28 which are secured to a shaft 29 journalled in the bracket 25. An arm 30 secured to the shaft 29 extends downwardly therefrom. A rod-31 is mounted to slide at one end through a rocking stud 32 in the lower end of the arm and at the other end through a lug 33 projecting {from a bracket 34 which is bolted to the loom side. A spring 35 is mounted upon this rod between the lug 33 and collars 36 and 37 which are adjustably. secured upon the rod 31 by set screws and are provided with cam faces to permit such relative adjustment as may be required to impose the proper tension upon the spring. The opposite end of the rod 31 is pivotally connected to a stud 38 upon an arm 39 which is pivotally mounted upon a stud 40 projecting from the bracket 34 and which constitutes a member of a compound pawl actuator. I

The arm 39 extends downwardly alongside the arm 41 of a pawl actuating lever and the arms 39 and 41 are provided with longi-' tudinal slots facing each other in which are rollers 42 and 43 carried by a radius bar 44 which will hereinafter be more fully described. The pawl carr'ing lever is pro vided with a downwardly extending arm 45 which is pivotally connected to one end of a link 46, the opposite end of which is provided with a slot which engages a pin upon some moving art of the loom, such as an arm extending rom the rocker shaft of the loom as is well u-nderstood by those familiar with the mechanisms of the patents above mentioned, and as shown in Fig. 4.

A pawl 47, which is pivotally mounted upon the upper end of the arm 41, engages the teeth 48 of a ratchet wheel 49 which is rotatably mounted upon the shaft 4. The extent of retracting movement of the pawl 47 is in the present construction, as in that disclosed in the patents aforesaid, dependent also upon the diameter of the yarn mass upon the warp beam. The radius arm 44, which supports the rollers 42 and 43 within the slots in the arms 39 and 41, is pivotally connected at its lower end to an arm 50 which is fixedly secured to a shaft 51 mounted in a suitable journal 52 and which is provided at its inner end with an arm 53 having at its upper end a head or follower 54 which rests upon the yarn mass upon the warp beam. As the diameter of the yarn mass increases, therefore, the head 54 will move toward the axis of the warp beam, thereby swinging the arm 50 downwardly, thus mov ing the radius rod 44 downwardly and bringing the rollers 42 and 43 more nearly to the axis of the shaft 4 about which the pawl actuating lever 41 oscillates. At the same time the downward movement of the roller 42 increases the effective length of the arm 39. Thus as the yarn mass grows smaller the effective retracting movement of the pawl 47 is increased and the effective forward movement thereof consequently increases in a proportion to rotate the ratchet wheel at a speed correlated to the required rate of warp beam let-off.

The ratchet 49 is provided with a brake drum 55 which is engaged by a suitable adjustable brake band 56 which is secured to an arm 57 having at its end a boss mounted upon 'the shaft 51 and which prevents the rotative movement of the brake. This brake acts to prevent rotation of the ratchet except when actuated by the pawl 47.

By virtue of the construction above described the ratchet 49 is rotated in accordance with the warp tension and the diameter of the yarn mass, as variations in the tension of the warp act upon the roll26 to swing the arm 28 downwardly, thereby moving the arm 30 forwardly and causing the same to move the rod 31 forwardly, thereby rocking the arm 39 upon its pivot and caus-' ing it in turn to rock the other arm 41 of the compound pawl carrier, thus retracting the pawl a distance correlated to the movement of the whip roll. The forward movement of the pawl is caused by the pull upon the link 46 acting through the arm 45 of the pawl carrying lever 41, thus advancing the pawl until it reaches a predetermined point. In the meantime the retractive position of the pawl is also controlled by the position of the rollers 42 and 43 upon the radius arm 44 which is positioned by the head 54 of the arm 53 which rests upon the yarn mass.

The rotation of the ratchet Wheel 49 is transmitted to the warp beam actuating shaft 4 through suitable speed reducing gearing operable to rotate said shaft in the same direction as the desired direction of warp delivery rotation of the Warp beam. In the preferred construction illustrated the ratchet 49 is provided with an eccentric 53, preferably formed as an integral extension of its hub. An internal gear 59 is mounted upon this eccentric,but is prevcnted'from revolution thereupon by suitable mechanism. As illustrated in Fig. 3 the disk of the internal gear is provided with a pair of out wardly extending lugs 60 which engage respectively slots 61 in arms (52 of a yoke 63 having an arm 64 provided at its lowerend with a slot 65 which embraces the shaft 51, thus preventing rotation of the internal gear while permitting it to move through the cycle of movement caused by the rotation of the eccentric upon which it is mounted. The teeth 66 of the internal gear 59 engage complementary teeth 67 upon a cooperatingspur gear 68 of smaller diameter than the internal gear 59 and consequently having a predetermined lesser number of teeth. The gear 68 may be fixedly secured to the shaft 4, but desirably is releasably secured thereto and also is removably mounted upon the shaft 4.

The internal gear 59 and the co-operating gear 68 may,'therefore, be considered a speed reducing unit which is removably mounted upon the shaft 4 and the eccentric 58 of the ratchet. By reason of the fact that the internal gear 59 has a greater number of teeth than the co-operating gear 68, each cycle of movement of the internal gear in a counter-clockwise direction, as illustrated by the mechanism shown in Fig; 1, will cause a partial rotation of the co-operating gear 68 in the opposite or clockwise direction a distance equal to the distance occupied by the number of teeth on'the internal gear in excess of those on the co-operating gear. Consequently the pinion 16 upon the warp beam actuating shaft 4 is rotated'in a clockwise direction which is the same direction as the desired direction of rotation of the warp beam. The idle gear 17, which is interposed between the pinion 17 r and the war beam gear, is rotated in a counterclockwise direction and in turn causes the warp beam gear, to rotate in a clockwise direction as required.

Any suitable means may be provided for releasably securing the co-operating gear 68 to the shaft 4. In the preferred construction illustrated a sleeve 69 having an enlarged head 7 0 is deta'chably secured upon the shaft 4 by a set screw 71. A removable feather or key, engaging the shaft-and sleeve, serves to prevent-relative rotation therebetween. The inner end of the sleeve 69 desirably abuts against'the hub of the gear 68 and retains it in rotatable engagement with the end of the eccentric 58. A hand wheel 72 is slidably mounted upon the sleeve 69 and connected thereto by a feather 7 3. The hub of the hand wheel and the face of the gear 68 are provided with interengaging teeth 74 operable when engaged to connect the'hand wheel to the gear. A helical spring 75, interposed between the head of the sleeve and the hub of the hand wheel 72, normally maintains such engagement.

Suitable means are provided for releasing the hand wheel from engagement with the gear 68. In the preferred construction a lever 76, which is fulcrumed upona stud 77 carried by a suitable bracket, is provided with a forked upper end the arms of which engage thefiat face 78 of the hub of the handwheel. "A downwardly-extending arm '79 of the lever 76 is provided with a stud 80 which engages a slot 81 in one arm of a lever 82 which is fulcrumed upon a stud 83 and prorided with a pedal 84:. By pressing the pedal 84 the lever 76 is actuated to slide the hand wheel 72 outwardly thereby releasing its teeth from engagement with the complementary teeth of the gear 68 so that by rotating the hand wheel 72 the warp beam actuating shaft 4 will be actuated directly manually to set or otherwise rotate the warp beam.

Desirably the end of the shaft 4 is also journalled in a bearing 85 in the arm 86 of a two-piece bracket, the members of which are adjustably connected by one or more boltsor screws 87, and the other member 88 of which is secured by bolts 89 to a bracket 90which is suitably secured to the loom side. By reason of this construction the portion of the shaft 4 upon which the speed reducingmechanism is mounted is rigidly supported and the bracket members 85 and 86 easily removable when it is desired to remove or replace the speed reducing mechanism as aforesaid.

By reason of the detachability of the speed reducing unit, other units of like character maybe employed, or a speed reducing unit substituted adapted to rotate the warp beam' actuating shaft in the reverse direction to the required let-off direction of rotation of the warp beam, so that a smaller warp beam having a usual standard gear may be mounted upon the usual bearings in the ends of the loom side and operated in the manner disclosed in the patents aforesaid. It will, therefore, be obvious that the present invention provides means for properly supporting upon a usual type of loom warp beams of much larger diameter than have heretofore been capable of use upon such looms, with automatically controlled mechanism for actuating the same in accordance with the warp tension and diameter of the mass of yarn upon the warp beam, and that the mechanism for accomplishing these purposes may be embodied in a usual type of loom without substantial modification of the general mechanisms thereof.

It will be understood that the particular embodiment ,of the invention disclosed herein is of an illustrative character and is not restrictive, that various other means may be utilized to rotate the warp. beam actuating shaft in the same direction as the required direction of rotation of the warp beam, and that other mechanisms, than a single idle gear, may be introduced between the warp beam shaft and the warp beam to transmit such rotation of the warp beam actuating shaft to the warp beam without modification of the gear ratio therebetween.

Having thus described the invention, what is claimed as new,.and desired to be secured by Letters Patent, is:

1. A loom comprising a warp beam having a shaft and a gear, a warp beam actuating shaft, a pinion thereon, means detachab y secured to the loom for supporting'the shaft of the warp beam at a greater distance from the warp'beam actuating shaft than the combined length of the radii of said gear and pinion, means for rotating the warp beam actuating shaft in accordance with the warp tension and the diameter of the yarn mass and in the same direction of rotation as the required warp delivery direction of rotation of the 'war beam andmeans operable by said warp eam actuating shaft to rotate said warp beam in said required warp delivery direction.

2. A loom comprising a warp beam having a gear, a warp beam actuating shaft, a pinion thereon, means for rotating said warp beam actuating shaft in accordance with the warp tension and the diameter of the yarn mass and in the same direction of rotation as the re uired warp delivery rotation of the' warp cam, and means intermediate of said pinion and gear operable to transmit rotation from said pinion to said gear without changing the gear ratio therehetween, wherebythe axis of said gear and pinion may be spacedapart a greater distance than the combined length of the radii of said gear and pinion.

3. A loom comprising a warp beam having a shaft and a gear, a warp beam actuating shaft, a pinion thereon, means supporting the shaft of said warp beam gear at a greater distance from the warp beam actuating shaft than the combined length of radii of said gear and pinion, an idle gear engaging said pinion and warp beam gear for transmitting rotation from said inion to said gear and means for rotating said actuating shaft in a direction which will cause said warp beam to rotate in a proper warp de livery direction.

4. A loom comprising a warp beam having a gear, a warp beam actuating shaft, a pinion thereon, means for rotating said warp beam actuating shaft. in accordance with the warp tension' and the diameter of the yarn mass and in the same direction of rotation as the required warp delivery direction of rotation of the warp beam, and an idle gear intermediate of said pinion and gear for causing said warp beam to rotate in said warp delivery direction.

5. A loom comprising a warp beam having a gear, a warp beam actuating shaft, a

pinion thereon, means for rotating said warp beam actuating shaft in accordance with the warp tension and-diameter of the yarn mass and in a direction which will permit employ vment of an idle; gear intermediateof said gear and pinion whereby the axis of the warp beam may be located at a greater distance from the axis of the actuating shaft than the combined length of the radii of said gear and pinion and means for permitting the removal and substitution of different idle gears whereby the axis of said warp beam gear may be located at different distances from the axis of said pinion to permit the use of warp beams of different diameters.

6. A loom comprising a warp beam having a gear, a warp beam actuating shaft, a pinion thereon, means for rotating said warp beam actuating shaft in accordance with the tension and diameter of the yarn mass and in a direction which will permit the'employment of an idle gear intermediate of said gear and pinion, whereby the axis of the warp beam may be located at a greater dis tance from the axis of the actuating shaft than the combined length of the radii of said gear and pinion, an idle gear engaging said pinion and warp beam gear, a bracket having means for adjustably and detachably supporting said idle gear adapted to permit the employment of idle gears of different diameters and thereby to permit different spacings .of the axes of said gear and pinion "shafts to enable the use of Warp beams of different sizes.

7. A loom comprising a warp beam having a gear, a warp beam actuating shaft, a pinion thereon, a ratchet rotatably mounted on said shaft, means for actuating said ratchet in accordance with the, tension of said warp and the diameter of the yarn mass,

a speed reducing unit intermediate of said ratchet and shaft operable to rotate said shaft comprising a non-rotatable internal gear mounted on said eccentric, a cooperating gear mounted on said shaft, means securing said cooperating gear to said shaft and an idle gear engaging said pinion and said warp beam gear. I

9. Aloom'comprising a warp beam having a gear, a warp beam actuating shaft, a pinion thereon, a ratchet rotatably mounted on said shaft provided with an eccentric, means for actuating said ratchet'in accordance with the tension of the warp and the diameter of the yarn mass, 'a speed reducing unit intermediate of said'ratchet and said shaft comprising a non-rotatable internal gear mounted on said eccentric, a cooperating gear mounted on said shaft, means rotatable with said shaft and slidably mounted thereon releasably engaging said cooperating gear and normally connecting yarn mass, a speed reducing unit intermediate of said ratchet and said shaft operable to rotate said shaft in the same direction as the warp delivery direction of said warp beam comprising a non-rotatable internal 15 gear removably mounted 'on said eccentric, a cooperating gear of lesser diameter rotatably and removably mounted on said shaft and removable means for securing said unit' upon said shaft and said cooperatin 20 gear to said shaft, an idle gear engaging sai pinion and warp beam ear and means detachably supporting sai idle gear.

In testimony whereof, I have signed my name to this specification.

EDWARD C. BURNHAM. 

